• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.798-802
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• 2010

Recently, a total of 74 Staphylococcus pseudintermedius isolates were collected from clinical cases of canine pyoderma and otitis externa in Korea. In this study, we examined in vitro fluoroquinolone resistance among those isolates using a standard disc diffusion technique. The results demonstrated that, except for one isolate, approximately 18.9% to 27.0% of the isolates possessed bacterial resistance to both veterinary- and human-licensed fluoroquinolones including moxifloxacin (18.9% resistance), levofloxacin (20.3% resistance), ofloxacin (24.3% resistance), ciprofloxacin (25.7% resistance), and enrofloxacin (27.0% resistance). Most surprisingly, 14 out of 74 (18.9%) isolates were resistant to all the five fluoroquinolones evaluated. Moreover, a PCR detection of the methicillin resistance gene (mecA) among the 74 isolates revealed that 13 out of 25 (52.0%) mecApositive isolates, but only 7 out of 49 (14.3%) mecA-negative isolates, were resistant to one or more fluoroquinones. Taken together, our results imply that bacterial resistance to both veterinary- and human-use fluoroquinolones becomes prevalent among the S. pseudintermedius isolates from canine pyoderma and otitis externa in Korea, as well as that the high prevalence of the mecA-positive S. pseudintermedius isolates carrying multiple fluoroquinolones resistance could be a potential public health problem.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.99-104
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• 2012

Otitis externa (OE) is a frequent disease in the ear canals of dogs. To identify the pathogens causing OE in dogs and to determine their antimicrobial resistances, specimens were collected from animal hospitals in Daejeon. The isolates were examined by morphological and biochemical tests, 16S rRNA analysis and antimicrobial susceptibility tests. We analyzed correlation between the isolated pathogens and external factors of dogs such as breed, age, gender, ear mite, hair in ears and experience with antibiotic therapy. Thirty three strains of bacteria were isolated from 26 of the 68 heads of dogs with OE. The most isolated bacteria were Enterococcus faecalis (E. faecalis) followed by Staphylococcus aureus (Sta. aureus), Sta. pseudointermedius, E. faecium, E. avium and Streptococcus canis (Strep. canis) in order of frequency of occurrence. Isolation frequency of Enterococcus spp. and Staphylococcus spp. were 51.5% and 45.5%, respectively. E. faecalis and E. faecium isolates showed VanB phenotype, which is resistant to vancomycin but sensitive to teicoplanin were 58% and 25%, respectively. Nine isolates among total twelve isolates of E. faecalis were isolated from the dogs treated with antibiotics. There was no methicillin-resistant Sta. aureus (MRSA), but were MR-Sta. pseudointermedius (MRSP) (57.1%) and vancomycin-resistant (VR)-Sta. pseudointermedius (14.3%) (VRSP) showing VanB phenotype. However, vanA, vanB and vanC genes were not detected in VR isolates from the dogs. Taken together, VR-Enterococcus spp. (VRE) is one of the major pathogens in domestic animals, as well as community-and hospital-acquired infection.

• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.171-180
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• 2022

The aim of this study was to investigate the prevalence of antimicrobial resistance and virulence factors in staphylococci isolated from canine otitis externa. A total 295 causative microorganisms were isolated. The most common isolated species were Staphylococcus (S) pseudintermedius (94 isolates) followed by Pseudomonas aeruginosa (60 isolates), S. schleiferi (25 isolates), Escherichia coli (23 isolates) and Proteus mirabilis (20 isolates). Staphylococci isolates were showed high resistance to penicillin (78.6%), erythromycin (55.9%), tetracycline (52.4%), clindamycin (51.7%) and ciprofloxacin (42.8%). Of the 145 staphylococci isolates, 49 (33.8%) methicillin-resistant staphylococci (MRS) were observed, distributed among S. pseudintermedius (n=34), S. schleiferi (n=6), S. epidermis (n=4), S. hominis (n=2), S. aureus, S. caprae and S. saprophyticus (n=1, respectively). Forty-three (87.8%) of 49 MRS and 10 (10.4%) of 96 methicillin-susceptibility staphylococci harbored mecA gene. About 80% of MRS were multidrug-resistant with resistance to at least one antibiotic in three or more antibiotic classes. Resistance genes blaZ (93/114, 81.5%), ermB (35/81, 43.2%), ermC (3/81, 3.7%), aacA-aphD (50/54, 92.5%), tetM (69/76, 90.7%) and tetK (6/76, 7.8%) were detected among resistant isolates. Virulence factors genes lukF and lukS were found in 100%(145/145) and 43.4%(63/145), respectively. Genes encoding ermA, eta, etb and tsst were not detected. To the best of our knowledge, this is the first study which investigated for the presence of genes encoding antimicrobial resistance and staphylococcal toxins in staphylococci isolated from canine otitis externa. A continuous monitoring and surveillance program to prevent antimicrobial resistance in companion animals is demanded.

• Journal of Veterinary Clinics
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• v.30 no.2
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• pp.100-106
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• 2013

A clinical trial was performed to assess clinical efficacy and/or reduction in relapses by gold-bead implantation into acupuncture points in dogs with canine chronic recurrent otitis externa (CCROE). Forty dog-patients randomly divided into two groups were diagnosed as suffering CCROE, having intact tympanic membranes and a history of recurrences. Treatments were: control group (CG), treated with commercially available antimicrobial otic droplets, dosed twice daily for 7 days; and experimental group (GBI- gold bead implants), treated as for CG plus the insertion of 13 gold-bead implants under light anesthesia. Overall per cent assessment of composite clinical progression and progression of individual clinical signs were recorded. Bilateral chronic external otitis was diagnosed in 60% of the cases and left or right otitis in 20% of the cases each. Logistic model for repeated measures analysis showed that GBI induced a better clinical recovery as far as lesion score of some clinical signs is concerned. The overall percent cures of each group showed statistically significant difference. A McNemar analysis revealed that higher number of relapses was observed in CG patients as compared to the GBI (P < 0.05). In particular during these days, lesion on the pinna showed in odd ratios analysis a 7:1 ratio (recurrence CG:GBI) and ear wax/pus (4:1) from D42 to D365. It is concluded that gold-bead implantation into acupuncture points improves resolution of some clinical signs and greatly reduce relapses in CCROE affected dogs after 1 year follow-up (98.75%).

• Journal of Veterinary Clinics
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• v.29 no.1
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• pp.1-7
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• 2012

Fifty-four dogs with otitis externa were enrolled in the study for the Evaluation of efficacy of a Hydrocortisone aceponate - Gentamicin - Miconazole otic combination ($Easotic^{(R)}$, Virbac, Carros, France). Otitis externa patients were treated by $Easotic^{(R)}$ once daily for 5 days and 2 days off treatment and evaluated on $7^{th}$ day. If otitis externa persisted, additional $Easotic^{(R)}$ treatment was administered once daily for 5 days and rested 2 days and reevaluated on $14^{th}$ day. For the evaluation of efficacy of $Easotic^{(R)}$, eight clinical signs were scored on a severity scale and infectious agents from ear sample were also graded using semi-quantitative scale at each visit. Sum of clinical scores and cytological scores was defined as Global Clinical Score. When $Easotic^{(R)}$ was applied once daily for 5 days, global clinical score was reduced 76.0%. When $Easotic^{(R)}$ was administered for 10 days, during first 5 days administration, 46.6% reduction of global clinical score was detected. During additional 5 days administration, 82.2% reduction of global clinical score was observed compared with Day 0. Any relevant adverse effect was not reported during the study in all cases. Thus, $Easotic^{(R)}$ treatment once daily for 5 days and 10 days appears to be effective and safe treatment for canine otitis externa.

• Journal of Veterinary Clinics
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• v.25 no.3
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• pp.159-164
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• 2008

This study was carried out to determine the therapeutic effect of injection-acupuncture (AP) with bee-venom (apitoxin) in cases of canine otitis externa (COE). Fifteen dogs with naturally-acquired otitis externa were used in this study. The dogs were divided into the following antibiotics group (control group), apitoxin group (experimental group A) and apitoxin combined with antibiotics group (experimental group B). All groups were treated by ear cleaning with normal saline once on day 1. The control group was treated with susceptible antibiotics, and experimental group A was given injection-AP with apitoxin $(100{\mu}g/head)$ at TH17 (Yi Feng), SI19 (Ting Gong), GB03 (Shang Guan) and TH03 (Zhong Zhu) bilaterally. Experimental group B was treated with susceptible antibiotics and injection-AP with apitoxin at the same acupoints as experimental group A. All the groups were treated 3 times/week for 2 weeks. The identity of the causative agents, the changes in the clinical signs, otoscopic findings, bacterial count in the auricular discharges, and total WBC counts and neutrophil/lymphocyte (N/L) ratio in the peripheral blood were investigated in all groups. In bacterial isolation, Staphylococcus spp. combined with Streptococcus spp. was detected higher than other agents. The bacterial cell count in experimental group A was significantly decreased at 2 weeks (p<0.01), and those in experimental group B was significantly decreased at 1 week (p<0.01) and 2 weeks (p<0.01) compared by those of control group, respectively. The changes of clinical score in experimental group B were significantly decreased at 2 weeks (p<0.01) compared by those of control group, but, those of experimental group A was similar to those of control group. The changes of total WBC counts and neutrophil/lymphocyte (N/L) ratio were no significant difference found. In conclusion, injection-AP with apitoxin is an effective treatment for COE and might be an alternative method for treating COE.

• Journal of Veterinary Clinics
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• v.34 no.5
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• pp.335-340
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• 2017

Methicillin-resistant staphylococci (MRS), which are often multi-drug resistant (MDR), are important pathogens in both human and veterinary healthcare. The purpose of this study was to characterize the antimicrobial resistance of MRS isolated from dog ears in Korea. From 827 dog ears, staphylococci were cultured from both ears with otitis externa (n = 161, 41.0%) and healthy ears (n = 135, 31.1%). The prevalence of coagulase-positive staphylococci (CoPS) in ears with otitis externa (58.4%) was significantly higher (p < 0.05) than in healthy ears (28.2%), while the prevalence of coagulase-negative staphylococci (CoNS) in healthy ears (74.8%) was higher (P < 0.05) than in ears with otitis externa (41.6%). Forty-six (35.1%) and 74 (44.8%) CoPS and CoNS isolates, respectively, were determined to be MRS. Antimicrobial resistance in MRS was most frequently observed for penicillin (76.7%), ampicillin (61.7%), kanamycin (61.7%), erythromycin (47.5%), tetracycline (47.5%), and trimethoprim/sulfamethoxazole (46.7%). Overall, the MDR isolates were resistant to significantly more (P < 0.05) antimicrobial agents tested than methicillin-sensitive staphylococci in this study. These results provide therapeutic guidelines for the treatment of otitis externa in dogs from Korean veterinary hospitals, and the significant associated health concern to companion animals and their human contacts.

• Journal of the korean veterinary medical association
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• v.27 no.11
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• pp.641-660
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• 1991

Preventive ear management, early detection and treatment of ear diseases, and effective follow-up evaluations are the best approach to eradicating ear diseases. Up to 50$\%$ of dogs with chronic otitis externa may have concurrent otitis media d

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.314-319
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• 2006

To determine the antimicrobial and anti-inflammatory efficacy of Opuntia ficus-indica for chronic otitis, we evaluated the effects of topical applications of the methanol extracts with 20 cases of dogs which had chronic malignant otitis by pathogens with antibiotic resistance. The dogs had revealed recurrent symptoms of malignant otitis and were not treated by conventional therapeutic agents. However, in this study, the clinical cure rates of Opuntia ficus-indica was 75% and the average alleviation period was $1.21{\pm}0.42$ week, and the mean recovery period was $1.06{\pm}1.06$ week after the initiation of treatment. As the results of this study, topical Opuntia ficus-indica extracts was found to be highly effective for the treatment of chronic malignant otitis with clinical cure rates of 75% within 1.06 weeks of therapy. Further evaluation of Opuntia ficus-indica extracts will allow us to establish and to optimize the therapeutic strategy for the malignant otitis in veterinary practice, and the potential usefulness of this complementary treatment on recurrent infectious pathology.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1937-1945
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• 2018

Malassezia pachydermatis is a commensal yeast found on the skin of dogs. However, M. pachydermatis is also considered an opportunistic pathogen and is associated with various canine skin diseases including otitis externa and atopic dermatitis, which usually require treatment using an azole antifungal drug, such as ketoconazole. In this study, we isolated a ketoconazole-resistant strain of M. pachydermatis, designated "KCTC 27587," from the external ear canal of a dog with otitis externa and analyzed its resistance mechanism. To understand the mechanism underlying ketoconazole resistance of the clinical isolate M. pachydermatis KCTC 27587, the whole genome of the yeast was sequenced using the PacBio platform and was compared with M. pachydermatis type strain CBS 1879. We found that a ~84-kb region in chromosome 4 of M. pachydermatis KCTC 27587 was tandemly quadruplicated. The quadruplicated region contains 52 protein coding genes, including the homologs of ERG4 and ERG11, whose overexpression is known to be associated with azole resistance. Our data suggest that the quadruplication of the ~84-kb region may be the cause of the ketoconazole resistance in M. pachydermatis KCTC 27587.